Criss-Cross Ruffing Clash Squeeze
This is board 28 (rotated) from the August 28, 2016 La Jolla unit game. The 6♦ slam is cold but only two out of 13 pairs found it and no pair found 6NT though four pairs played in a notrump game. One enterprising E-W pair seems to have found a 6♥ sacrifice and suffered -1100 for it. So merely finding the minor suit slam was worth a 96% board, quite a bit better than the 79% minor suit slam expectation from the Slam Statistics article.
But for a top board, declarer needed to find the squeeze to edge out the other 6♦ declarer.
Suppose West leads the ♠K. Declarer wins and searches for the thirteenth trick. There is no finesse, so declarer must either ruff out ♠KQx in West’s hand, catch a very lucky ♣QJ doubleton, or look for a squeeze. It's clear from the lead that West guards spades. With four heart honors out, both defenders almost certainly guard hearts, so hearts cannot be part of simple squeeze. If the ♣T were in dummy, a black suit squeeze would operate against West if he holds both the ♣Q and ♣J. Perhaps a double squeeze with hearts as the pivot suit can work. Declarer might aim to reduce to something like:
On the lead of the last diamond, both defenders have to throw a heart to keep the black suits guarded and the ♥6 scores the last trick. This squeeze works when East has both the ♣J and the ♣Q club guards. There is just one problem though: declarer started with ♥93 ♣KT rather than ♥9 ♣KTx. So this position is impossible.
Maybe there is another way to use all three suits in a squeeze. This is going to require club and spade length in dummy and therefore the heart menace will have to be the long heart in hand. The defense has easy discards until this position:
Dummy’s two entries make the ♠T9 a ruffing menace. The combined club holding is a clash menace that ties up all of the defender’s clubs. The heart situation is a more normal menace but being a blocked xx vs. A instead of the simple Ax vs. x, the position resembles a criss-cross squeeze.
When declarer plays a diamond, each defender can only spare a heart. Now after the ♥A, a spade ruff squeezes East in hearts and clubs. If it hadn’t been for the ruffing spade menace, West could have guarded hearts.
Now suppose West leads a high heart. Declarer takes the ♥A, draws trump in one round, cashes the ♣K, and rattles off trump. West can afford to pitch his heart guard and one spade because there are only two entries to dummy but difficulties arise in this position:
On the second to last trump, West must release a club, establishing the club clash menace, as dummy and East pitch spades. Now after the ♠A, a spade ruff squeezes East once again in hearts and clubs. If West hadn’t had to guard against the establishment of spades, he could have kept a heart guard.
A club or diamond lead reduces to the one of the two situation above at declarer’s choosing.
The ♣T is the real hero of this squeeze. The two lowest spades in dummy and the two low hearts in hand could be any two cards. If declarer had the ♣J and east held the ♣T, the clash menace would still exist, but simply finessing the ♣J would be the percentage play. If declarer had the ♣9, West would improbably need all the higher clubs, the ♣QJT, and East would need to the ♣8 over dummy’s ♣7 to preserve the clash menace. If declarer had the ♣8, West would need the ♣QJT9 and one fewer heart, and East would need the ♣7 over a smaller card in dummy. The ♣T is the one card that makes this squeeze at all likely and simultaneously worth trying.
In this hand the constipated ♣KT (or equivalently the ♣AT), like the queen-doubleton in Lady Lavender, is a keeper of dark endplays.